       (is (= user-selection-set (:selection-set user-selection)))
       (is (= [{:node-type :field :field-name "name"}] (collect-fields user-selection-set nil)))
       (is (= "Test user name" (get-in (execute nil simple-user-schema customized-resolver-fn query) [:data "user" "name"]))))))
+
+(deftest test-default-argument-value
+  (testing "test execution of default argument value"
+    (let [schema simple-user-schema
+          query "query {loremIpsum}"
+          context nil]
+      (is (= "Lorem" (-> (execute context schema customized-resolver-fn query)
+                         :data
+                         (get "loremIpsum")))))))
 
 (deftest test-execution-on-list
   (testing "test execution on list"

      ["QueryRoot"  "user"] (fn [& args]
                              {:name "Test user name"
                               :nickname "Test user nickname"})
      ["User" "son"] (fn [context parent & args]
                       {:name "Test son name"
                        :nickname "Son's nickname"})

            [graphql-clj.type :as type]
            [graphql-clj.parser :as parser]
            [graphql-clj.introspection :as introspection]
            [clojure.core.match :as match]
            [clojure.string :as str]))

(def simple-user-schema-str
  "type User {
